You can use the MMC Forensic Narcotics Tests along side the MMC Presumptive Field Tests to get an extra confirmation because the MMC Forensic Narcotics Tests have fewer crossreactions than the MMC Presumptive Field Tests. Furthermore with the MMC Forensic Narcotics Tests you can swab a surface and test it because these tests have a verry high sensitivity, a sample containing only a few hunderd nanograms of substance will be enough to test positively besides this the tests are verry accurate (99-99.8%). Also liquid testing is one of the posibility's.